An unmanned vessel is a vessel without a human controller aboard, e.g., unmanned aerial vehicle, unmanned marine craft, or an unmanned land vehicle. Its navigation is controlled either autonomously by onboard computers or by a remote control of an operator on the ground or in another vehicle. Unmanned vessels are usually deployed for military and special operation applications, but are also used in a growing number of civil applications, such as policing and firefighting, and nonmilitary security work, such as inspection of power or pipelines.
Historically, unmanned vessels were simple remotely controlled vessels, but autonomous control is increasingly being employed. The rise in autonomously controlled vessels had led to global positioning systems being installed on such vessels, which facilitates navigation of the unmanned vessel.